How do you calculate capacity on a process capacity sheet?

Divide the available operating time in a shift by the sum of the per-piece completion time (manual time plus auto time) and the tool-change time per piece (change time divided by pieces between changes). The result is good pieces per shift for that machine. Compare every machine and the lowest number is the constraint that sets the whole process rate.

What are the three standardized-work documents?

The process capacity sheet, which gives capacity per machine; the standardized work combination table, which shows how manual, auto, and walk time fit within takt time; and the standardized work chart, which shows the layout and standard in-process stock. All three rest on takt time, a defined work sequence, and standard in-process stock, and the capacity sheet comes first.

Why does the process capacity sheet include tool-change time?

Because tool changes are a real, recurring capacity loss that a simple cycle-time estimate ignores. A machine with a fast per-piece time can still be the bottleneck if it needs a long tool change every few dozen pieces. The sheet forces you to write the change interval and time and spread that loss across the run, turning an invisible drain into a number.

What is the difference between capacity and output?

Capacity is what a machine can make per shift under standard conditions, including planned stops and tool changes but assuming the process runs to standard. Actual output is usually lower because it also loses time to unplanned downtime, quality problems, and other losses. The capacity sheet computes capacity; downtime and OEE reckon with the gap between capacity and real output.

How does a process capacity sheet relate to line balancing?

The capacity sheet tells you what each machine can produce; takt time tells you what the line must produce; and line balancing reconciles the two by moving work off constrained machines onto ones with spare capacity. You cannot balance a line honestly without the capacity sheet, because only it identifies which machines have room and which are the true constraints.

How often should you update a process capacity sheet?

Whenever the process changes and periodically even when it does not, because tool life, machine condition, and operator method all drift over time. A capacity sheet timed once and filed becomes a snapshot of a line that no longer exists. Capturing manual time, machine cycle, and stops live at the station keeps the sheet current instead of stale.

The Process Capacity Sheet

Document each machine's manual time, cycle, and tool-change loss to find the true bottleneck before you balance the line, not after.

A process capacity sheet is a standardized-work form that records, for each machine in a linked process, the manual time, the automatic machine time, and the tool-change time and interval, then calculates how many parts that machine can make per shift, so you can find the real bottleneck before you balance the line.

It is the least glamorous of the three standardized-work documents and the one that saves the most bad decisions. Balance a line by eye and you almost always protect the wrong station; a process capacity sheet replaces the eye with arithmetic, machine by machine, including the tool changes that quietly eat capacity nobody counted. This guide covers what goes on the sheet, how the capacity math actually works, and how the sheet feeds line balancing and takt.

What is a process capacity sheet?

A process capacity sheet is one of the three core forms of Toyota-style standardized work, alongside the standardized work combination table and the standardized work chart. The Lean Enterprise Institute defines standardized work as built on three elements, takt time, the work sequence, and the standard in-process stock, and documented on these shop-floor forms (Lean Enterprise Institute, Standardized Work). The capacity sheet is the one that answers a single blunt question: how many good parts can each machine in this process actually produce in the time available?

The word capacity here is specific. It is not the nameplate rating a vendor prints on a machine; it is the real, sustainable output once you subtract the time the machine spends changing tools and account for the manual work an operator must do at it. Those two subtractions are exactly what a casual estimate misses, and they are why the slowest station on paper is often not the true constraint on the floor.

What goes on a process capacity sheet?

The sheet is a row per machine and a handful of columns that build up to a capacity number. The columns matter because each one is a place capacity leaks.

Column	What it records	Why it matters
Process / machine	Step number, part, and machine ID	Ties the row to a real station in sequence
Manual time	Operator hand time at the machine per piece	Work that cannot run in parallel with the machine
Auto (machine) time	Unattended machine run time per piece	Runs while the operator moves on
Completion time	Manual plus auto time for one piece	The base per-piece time before tool changes
Tool-change interval	Pieces made between tool changes	How often you pay the change penalty
Tool-change time	Minutes to swap the tool	Capacity lost to setup, spread over the run
Capacity	Good pieces per shift for this machine	The number you compare across the line

Each row of a process capacity sheet builds from manual and auto time to a per-piece completion time, then subtracts the tool-change penalty to land on a real capacity per shift. The tool-change columns are what a casual estimate leaves out.

The two tool-change columns are the sheet's whole reason for existing. A machine with a 20-second completion time looks fast until you learn it needs a five-minute tool change every 50 pieces, at which point six seconds per piece vanish into changeovers. Only a form that forces you to write the interval and the change time turns that invisible loss into a number.

A capacity sheet row builds manual and auto time into a completion time, then folds in the tool-change interval and time to produce a real capacity per shift, the number you compare across machines.

How do you calculate capacity on the sheet?

The core formula divides the time you have by the time each piece really costs, including its share of tool changes. Written plainly:

Capacity per shift = available operating time / (completion time per piece + tool-change time per piece) where completion time is manual plus auto time, and tool-change time per piece is the change time divided by the number of pieces made between changes.

Set the available operating time. Take the shift length and subtract planned stops, breaks, meetings, and scheduled maintenance. This is the real time the machine can run, in seconds.
Measure manual and auto time. Time the operator's hand work at the machine and the machine's unattended run time, per piece, by observation, not from the spec sheet.
Add them into completion time. Completion time per piece is manual time plus auto time, the base cost of one good part before tool changes.
Convert the tool change to a per-piece cost. Divide the tool-change time by the number of pieces made between changes. A five-minute change every 50 pieces is six seconds per piece.
Divide to get capacity. Divide available operating time by the sum of completion time and tool-change time per piece. The result is good pieces per shift for that machine.
Repeat for every machine and compare. The machine with the lowest capacity is the constraint, and it sets what the whole process can actually deliver.

Worked once, the arithmetic is simple; the value is in doing it for every machine with honest, observed numbers. That is when the surprise usually lands: the station everyone blamed is fine, and a quiet machine two steps upstream, bleeding capacity to frequent tool changes, is the true constraint.

Plotting each machine's capacity against demand exposes the constraint at a glance. Here M3 falls below the required rate, so it, not the loudest station, is where every improvement hour should go.

By the numbers: the three standardized-work documents

The process capacity sheet is not a standalone worksheet; it is the foundation of a set. Toyota-style standardized work is documented on three linked forms, the process capacity sheet (capacity per machine), the standardized work combination table (how manual, auto, and walk time fit within takt), and the standardized work chart (layout and standard in-process stock), and all three rest on takt time, a defined work sequence, and standard in-process stock (Lean Enterprise Institute, Standardized Work). The capacity sheet comes first because the other two need its numbers: you cannot combine work against takt until you know what each machine can actually produce. Where Harmony fits: a capacity sheet is timed by hand on one good day, but tool wear, changeover skill, and micro-stops shift the real numbers shift to shift. When manual time, machine time, and stops are captured live at each station, the capacity on the sheet reflects the line as it runs now, not as it ran the morning someone stood there with a stopwatch.

The process capacity sheet is the first of the three standardized-work documents; its machine capacities feed the combination table and the work chart, all resting on takt time.

How does the capacity sheet relate to takt and line balancing?

The capacity sheet answers "what can each machine make?"; takt time answers "what must the line make to meet demand?"; and line balancing is the act of reconciling the two. You cannot balance a line honestly without the capacity sheet, because balancing means moving work off the constraint and onto machines with spare capacity, and only the sheet tells you which machines those are. Compare each machine's capacity to the takt requirement, and any machine below it is a constraint you must break, by cutting its tool-change loss, offloading manual work, or reducing its cycle, before the line can hold rate.

This is also where the capacity sheet meets flow. A value stream map shows where material waits across the whole plant; the capacity sheet zooms into one process and explains why a step cannot keep up, in terms of manual time, machine time, and tool changes you can actually attack. The two work together: the map finds the slow process, the capacity sheet finds the slow machine inside it.

What are the most common capacity sheet mistakes?

The first is using nameplate or spec numbers instead of observed ones. A machine's rated cycle is a marketing figure; its real completion time includes the operator's hand work and the small hesitations that never make the brochure. The second is ignoring tool changes, which is the exact loss the sheet exists to capture, and the most common way a bottleneck stays hidden.

The third is treating the sheet as a one-time study. Tool life shifts as materials and speeds change, operators get faster or slower, and a machine that had spare capacity in January is the constraint by June. A capacity sheet timed once and filed is a snapshot of a line that no longer exists. The fourth is confusing capacity with output: capacity is what a machine can make under standard conditions, while actual output also loses time to unplanned downtime which belongs in a separate reckoning.

How does a process capacity sheet connect to the floor?

The capacity sheet is the arithmetic backbone of standard work and it feeds directly into line balancing takt planning, and constraint management. It also pairs naturally with a product-quantity analysis: once you know which products run in volume, you build capacity sheets for the machines those high-runners depend on, and design flow around the real constraints. All of it lives inside lean manufacturing where the whole point is to make the line produce to takt without heroics.

The hard part is keeping the numbers true. A capacity sheet is only as good as its inputs, and its inputs, manual time, machine time, tool-change frequency, all drift the moment you stop watching. Timed by hand, they are accurate for a day and stale by the next changeover. When manual time, machine cycle, and every stop are captured live at each station, the capacity sheet can be recomputed against reality, and a machine sliding toward the constraint shows up before it starves the line. That live picture is what Harmony gives a plant through station-level capture and it is the difference between a capacity sheet that guides balancing and one that misleads it. CLS made exactly that shift, from cycle and stop data found the next morning to data visible during the shift. No rip-and-replace.